Particles/Hair: How do I adjust the normal so the spikes go the same way around the object?
After a lot of web digging and experimenting, the answer was in the manual!

In the Particles panel enable the Rotation option, and set Initial Orientation to Normal-Tangent. BUT you need to have created a UV map for this to work.

Depending on the shape of your faces, the UV Reset option in UV Mapping drop down can be useful setting the initial rotation too.